perhaps... Some kind of predator or enemy drove them to live up there. Baboons will sleep in caves or on cliffs to avoid predation. What other advantage can be gained from the exertion, the danger, etc. I would imagine the nursery / daycare is up there. The kids probably just stayed up there in those houses. And what about the elderly? The whole thing is a mystery. Very interesting. Right up my alley.
RE: The Mystery Of The Anasazi: Part Three